Absorbable, reduced-pressure manifolds and systems

ABSTRACT

A reduced-pressure treatment system includes an isolation device for isolating a tissue site from surrounding tissue for reduced-pressure treatment that is formed from a first material having a first bio-absorption term and at least a second material having a second and different bio-absorption term. The different materials allow the isolation device initially to function well for reduced-pressure treatment and then to experience degradation at a quicker pace which facilitates healing. In addition, a reduced-pressure manifold for treating a tissue site is presented that includes a flexible barrier member formed from a first material, which has a first bio-absorption term and formed with a first plurality of apertures; a second material, which has a second bio-absorption term, disposed within the plurality of apertures; wherein the first bio-absorption term is greater than the second bio-absorption term; and a reduced-pressure delivery member coupled to the barrier member for delivering reduced pressure to the second surface of the barrier member during reduced-pressure treatment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/491,845 filed Jun. 25, 2009, which claims the benefit, under35 U.S.C. §119(e), of the filing of U.S. Provisional Patent ApplicationSer. No. 61/075,699, entitled “Absorbable, Reduced Pressure Manifold andSystem,” filed Jun. 25, 2008, and that application is incorporatedherein by reference for all purposes.

BACKGROUND

The present invention relates generally to medical treatment systems andin particular to absorbable, reduced-pressure manifolds and systems.

Clinical studies and practice have shown that providing reduced pressurein proximity to a tissue site augments or accelerates the growth of newtissue at the tissue site. The applications of this phenomenon arenumerous, but application of reduced pressure has been particularlysuccessful in treating wounds. This treatment (frequently referred to inthe medical community as “negative pressure wound therapy,” “reducedpressure therapy,” or “vacuum therapy”) provides a number of benefits,including faster healing and increased formulation of granulationtissue. Typically, reduced pressure is applied to the tissue through aporous pad or other manifold device. The porous pad contains cells orpores that are capable of distributing reduced pressure to the tissueand channeling fluids that are drawn from the tissue. The porous pad maybe incorporated into a dressing having other components that facilitatetreatment. Reduced pressure therapy also has been applied to treatsubcutaneous wounds and to promote bone regeneration.

SUMMARY

Shortcomings with certain aspects of reduced-pressure treatment systemsare addressed by the present invention as shown and described in avariety of illustrative embodiments herein. According to an illustrativeembodiment, a reduced-pressure manifold for treating a tissue siteincludes a barrier member formed from a first bioabsorbable material andhaving a first surface and a second, tissue-facing surface. The barriermember is formed with a first plurality of apertures. The first materialhas a first bio-absorption term (BA₁). A second bioabsorbable materialis disposed within the plurality of apertures and is operable to form atemporary seal. The second material has a second bio-absorption term(BA₂). The first bio-absorption term is different than the secondbio-absorption term (BA₁≠BA₂). The reduced-pressure manifold may alsoinclude a reduced-pressure delivery member coupled to the barrier memberfor delivering reduced pressure to the second surface of the barriermember during treatment.

According to another illustrative embodiment, a reduced-pressurepressure delivery system for percutaneous delivery of reduced pressureto a tissue site includes a reduced-pressure manifold formed from afirst material having a first bio-absorption term and a second materialhaving second bio-absorption term. The reduced-pressure manifold has aninsertion position and an activation position. The system furtherincludes a reduced-pressure delivery member having a distal end with atleast one delivery aperture for delivering reduced pressure to thetissue site and an insertion device for percutaneously delivering thereduced-pressure manifold and the distal end of the reduced-pressuredelivery tube to the tissue site and transitioning the reduced-pressuremanifold from the insertion position to the activation position. Thefirst bio-absorption term may be greater than the second bio-absorptionterm.

According to another illustrative embodiment, a reduced-pressuretreatment system includes an isolation device for isolating a tissuesite from surrounding tissue for reduced-pressure treatment. Theisolation device includes a first material having a bio-absorption term(BA₁) and a second material having a second and different bio-absorptionterm (BA₂). The system further includes a reduced-pressure source forproviding a reduced pressure and a reduced-pressure delivery conduitfluidly coupling the isolation device and the reduced-pressure source.

According to another illustrative embodiment, a method of manufacturinga reduced-pressure manifold includes the steps of: forming a flexiblebarrier member from a first material having a first bio-absorption term(BA₁). The flexible barrier member has a first surface and a second,tissue-facing surface. The method further includes forming a firstplurality of apertures in the barrier member and disposing a secondmaterial in the first plurality of apertures. The second material has asecond bio-absorption term (BA₂). The first bio-absorption term isdifferent than the second bio-absorption term (BA₁≠BA₂).

According to another illustrative embodiment, a method for treating atissue site with reduced pressure includes the step of using areduced-pressure delivery member to deploy a reduced-pressure manifoldproximate the tissue site. The reduced-pressure manifold includes abarrier member formed from a first material, which has a firstbio-absorption term (BA₁), and having a first surface and a second,tissue-facing surface. The barrier member is formed with a firstplurality of apertures. The apertures have a second material disposedwithin the plurality of apertures whereby a temporary seal is formed.The second material has a second bio-absorption term (BA₂). The firstbio-absorption term is different from the second bio-absorption term(BA₁≠BA₂). The method further includes coupling a reduced-pressuredelivery member to the barrier member for delivering reduced pressure tothe second surface of the barrier member during treatment. The methodfurther includes providing reduced-pressure to the reduced-pressuremanifold; removing the reduced-pressure delivery member; and allowingthe reduced-pressure manifold to absorb.

According to another illustrative embodiment, a reduced-pressuremanifold for treating a tissue site includes a barrier member formedfrom a material and having a first surface and a second, tissue-facingsurface and wherein the barrier member is formed with a first pluralityof material portions having a first thickness (t₁) and a secondplurality of material portions having a second thickness (t₂). The firstthickness (t₁) is greater than the second thickness (t₂). An effectivebio-absorption term of the first plurality of material portions isgreater than an effective bio-absorption term of the second plurality ofmaterial portions. The manifold may further include a reduced-pressuredelivery member coupled to the barrier member for delivering reducedpressure to the second surface of the barrier member during treatment.

Other features and advantages of the illustrative embodiments willbecome apparent with reference to the drawings and detailed descriptionthat follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, perspective view of an illustrative embodiment ofa system for delivering reduced-pressure to a tissue site;

FIG. 2 is a schematic, perspective view of an illustrative embodiment ofa reduced-pressure manifold;

FIG. 3 is a schematic cross-section of the reduced-pressure manifold ofFIG. 2;

FIG. 4 is a schematic cross-section of another illustrativereduced-pressure manifold;

FIG. 5 is a schematic cross-section of another illustrativereduced-pressure manifold;

FIG. 6 is a schematic cross-section of another illustrativereduced-pressure manifold;

FIG. 7 is a schematic cross-section of another illustrativereduced-pressure manifold;

FIG. 8 is a schematic, perspective view of another illustrativeembodiment of a reduced-pressure manifold;

FIG. 9 is a schematic, perspective view of another illustrativeembodiment of a reduced-pressure manifold;

FIG. 10 is a schematic, bottom (tissue side) view of an illustrativeembodiment of a reduced-pressure manifold and insertion device;

FIG. 11A is a schematic, bottom (tissue side) view of an illustrativeembodiment of a reduced-pressure manifold for percutaneous insertion;

FIG. 11B is a schematic, bottom (tissue side) view of the illustrativeembodiment of a reduced-pressure manifold of FIG. 11A showingactivation; and

FIG. 11C is a schematic, bottom (tissue side) view of thereduced-pressure manifold of FIG. 11A showing the manifold in anactivated position.

DETAILED DESCRIPTION

In the following detailed description of the illustrative embodiments,reference is made to the accompanying drawings that form a part hereof.These embodiments are described in sufficient detail to enable thoseskilled in the art to practice the invention, and it is understood thatother embodiments may be utilized and that logical structural,mechanical, electrical, and chemical changes may be made withoutdeparting from the spirit or scope of the invention. To avoid detail notnecessary to enable those skilled in the art to practice the embodimentsdescribed herein, the description may omit certain information known tothose skilled in the art. The following detailed description is,therefore, not to be taken in a limiting sense, and the scope of theillustrative embodiments are defined only by the appended claims.

Referring to FIG. 1, an illustrative reduced-pressure delivery system100 is shown treating a tissue site 102, which in this illustration is abone 104. When used to promote bone tissue growth, reduced pressuretissue treatments may increase the rate of healing associated with afracture, a non-union, a void, or other bone defect; help improverecovery from osteomyelitis; increase localized bone densities inpatients suffering from osteoporosis; or speed and improveoseointegration of orthopedic implants such as hip implants, kneeimplants, and fixation devices. As used herein, “or” does not requiremutual exclusivity. The reduced-pressure delivery system 100 may be usedon these tissue types and sites as well as others. In this illustrativeembodiment, the reduced-pressure delivery system 100 is shown treating abone fracture 106.

The reduced-pressure delivery system 100 includes a reduced-pressuresource 160 that may take many different embodiments. Thereduced-pressure source 160 provides reduced pressure as a part of thereduced-pressure delivery system 100. The term “reduced pressure” asused herein generally refers to a pressure less than the ambientpressure at a tissue site that is being subjected to treatment. In mostcases, this reduced pressure will be less than the atmospheric pressureat which the patient is located. Alternatively, the reduced pressure maybe less than a hydrostatic pressure of tissue at the tissue site.Although the terms “vacuum” and “negative pressure” may be used todescribe the pressure applied to the tissue site, the actual pressureapplied to the tissue site may be significantly more than the pressurenormally associated with a complete vacuum. Unless otherwise indicated,values of pressure stated herein are gauge pressures.

The reduced pressure delivered by the reduced-pressure source 160 may beconstant or varied (patterned or random) and may be deliveredcontinuously or intermittently. In order to maximize patient mobilityand ease, the reduced-pressure source 160 may be a battery-powered,reduced-pressure generator. This facilitates application in theoperating room and provides mobility and convenience for the patientduring the rehabilitation phase. Other sources of reduced pressure mightbe utilized such as V.A.C.® therapy unit, which is available from KCI ofSan Antonio, Tex., wall suction, or a mechanical unit.

The reduced pressure developed by the reduced-pressure source 160 isdelivered through a reduced-pressure delivery conduit 170, or medicalconduit or tubing, to a reduced-pressure manifold 110. An interposedhydrophobic membrane filter may be interspersed between thereduced-pressure conduit 170 and the reduced-pressure source 160. Thereduced-pressure manifold 110 may be surgically or percutaneouslyinserted into the patient and placed proximate the bone fracture 106.When percutaneously inserted, the reduced-pressure delivery conduit 170may be inserted through a sterile insertion sheath that penetrates theepidermis of the patient. The reduced-pressure manifold 110 includes atleast two materials having different absorption terms.

Referring now primarily to FIGS. 2 and 3, an illustrative embodiment ofa reduced-pressure manifold 210 is presented. The reduced-pressuremanifold 210 includes a barrier member 212 that is formed as a barrierbody 214 from a first material 216, which may be rigid or flexible. Thereduced-pressure manifold member 210 may function as an isolation devicethat includes a flexible barrier member for maintaining reduced pressureproximate the tissue site.

The barrier body 214 of the barrier member 212 has a first surface 218and a second, treatment-facing (or tissue-facing) surface 220. A firstplurality of apertures 222 is formed in the barrier body 214. Theapertures 222 may be filled with a second material 224. The apertures222 may completely cover the barrier body 214 as shown in FIG. 2 or maypartially cover the barrier body 214. The apertures 222 may be randomlyapplied or applied in various patterns such as the uniform pattern shownin FIG. 2. The barrier body 214 is presented as a plane of material, butit could also be formed into various shapes and contours for applicationto different tissue sites.

During treatment, the barrier body 214 helps apply reduced pressure tothe tissue site and to preventingress of potentially interfering tissueduring the treatment phase. Once treatment is completed it may bedesirable for the treated tissue to be in chemical communication withother tissues that were previously subjected to the barrier body 214.The inclusion of additional materials that absorb relatively quickly inthe reduced-pressure manifold 210 helps speed this communication. Therelative absorption rates of the materials and other design features maybe controlled to achieve various effects.

In choosing the first material 216 and second material 224, a number ofdesign parameters may be considered. The first material 216 may beselected to provide mechanical properties such as strength in order toprovide the necessary structure for the reduced-pressure treatment usingthe reduced-pressure manifold 210. At the same time, once treatment iscomplete, it may be desirable for the reduced-pressure manifold 210 tobe absorbed and degrade as quickly as possible or at least to begin thechemical communication of the treatment tissue with other surroundingtissues that were previously subjected to the barrier member 212 of thereduced-pressure manifold 210. This latter consideration may becontrolled by a number of design parameters such as the absorption rateor absorption term of the second material 224, the diameter of theapertures 222, the thickness of barrier body 214, etc. For example, asmall diameter aperture in a thick body 214 will have less mechanicalimpact and a slower degradation than a larger diameter pore in a thinbody 214. In other situations, lasting mechanical strength may bedesirous and maintenance of portions of the manifold 210, e.g., theportions composed of material 216, as a tissue stabilizing element maybe achieved by tissue growing through the apertures 222. In this casethe first absorption rate BA₁ (see below) may be selected for aclinically relevant duration and BA₂ may selected to absorb faster toenable trans-aperture tissue growth.

The first material 216 has a given absorption rate that results in afirst bio absorption term (BA₁), and the second material 224 has a givenabsorption rate that results in a second bio-absorption term (BA₂).Numerous materials may be used for materials 216 and 224. For example,the first material 216 may be a polyglycolic acid material with anabsorption time or term (BA₁) of several months, and the second material224 may be a dried gelatinous material having an absorption time or term(BA₂) of only several days or less. Other suitable bio-absorbablematerials may include, without limitation, a polymeric blend ofpolylactic acid (PLA) and polyglycolic acid (PGA). The polymeric blendmay also include without limitation polycarbonates, polyfumarates, andcapralactones. Either the first material 216, the second material 224,or both may be a porous material having interconnected cells that permitfluid flow through the material, or the materials may be impervious tofluids.

The absorption terms of the materials may be chosen in differentcombinations for different purposes. If the first material is apolyglycolic acid material and the second material is dried gelatinousmaterial, then the first bio-absorption term (BA₁) will be greater thanthe second bio-absorption term (BA₂), i.e., BA₁>BA₂. In otherembodiments, the materials may be selected the other way, i.e., BA₂>BA₁.The first material 216 and second material 224 may also be covered by athird material that reduces the rate of degradation of the secondmaterial 224 as another control mechanism.

The absorption of one of the materials, e.g., the second material 224,may open up pore sizes, or apertures 222, that are adequate to achieve adesired purpose. For example, in one illustrative embodiment, the poresize may be large enough to allow chemical signaling, but small enoughto restrict cell migration. In a more specific example, with sometissues, a pore size of about 50 microns would prevent cell migrationfor the tissues involved, but would allow chemical signaling. The poreactual size desired would vary some depending on the tissues involved.Alternatively, the pore size may intentionally be sized to allow cellmigration or trans-aperture growth after one of the materials isabsorbed. A third material may be added to allow for delivery of amedicine or other substances and may be designed to become availableonly after one of the other two materials is absorbed or some portionthereof.

Numerous combinations are possible to accommodate different situations.A few examples follow. In the first illustrative example, the firstbio-absorption term (BA₁) is at least one month and the secondbio-absorption term (BA₂) is less than one week under typical conditionsfor the deployed reduced-pressure manifold 210. In another illustrativeexample, the first bio-absorption term (BA₁) is at least one week andthe second bio-absorption term (BA₂) is less than three days. In a thirdillustrative example, the first bio-absorption term (BA₁) is at leasttwo days and the second bio-absorption term (BA₂) is less than one day.In still another illustrative example, the first bio-absorption term(BA₁) is on the order of about 90 days and the second bio-absorptionterm (BA₂) is on the order of about 10-14 days. In still anotherillustrative example, the first bio-absorption term (BA₁) is longer than90 days and the second bio-absorption term (BA₂) is shorter than 10days. In some situations, the first bio-absorption term (BA₁) may be onthe order of years or even decades. Again, numerous possibilities existand moreover a third material may be included and other parameters, suchas the thicknesses, may be varied as well. If a third material is added,the third material may be in the form of deposits, e.g., balls, of athird material, formed within the first material 216 to make the firstmaterial 216 more porous once the third material is absorbed or disposedin apertures (see FIG. 4).

The ratio of the thickness of the first material 216 to the diameter orwidth of the apertures 222 may be selected to control or adjust thebio-absorption properties of the manifold 210. For example, an aperturehaving a small diameter in a relatively thick sheet would have lessmechanical impact and a slower absorption rate than a large diameteraperture in a thinner sheet. The first material 216 and the secondmaterial 224 may optionally be coated with other materials that mayretard the absorption of the first material 216, the second material224, or both.

In another illustrative embodiment, the materials may be selected suchthat BA₂ is greater than BA₁ (i.e., BA₂>BA₁). In that situation, thedistributed second material that remains after the first material isabsorbed will not typically resist motion of the tissue or offermechanical functionality to the area. Many other combinations arepossible with respect to the materials and parameters mentioned.

The manifold body 214 is schematically shown in the illustrativeembodiment of FIG. 2 as a planar, thin member, but a non-planar member,e.g., a thicker member or varied shape member, may be used as thethicker member may be advantageous in some clinical situations.Moreover, as noted, variations on the apertures and materials (see,e.g., FIGS. 3, 4, 5, 6, and 7) may be used to construct thereduced-pressure manifold 210, or barrier, with differential absorptioncharacteristics. For a more specific illustrative example, areduced-pressure manifold 210 may be formed from a first material (withBA₁) of polyglycolic acid (PGA) formed into a felted mat, such a feltedmat is available from Biomedical Structures, LLC of Warwick, R.I., andfrom a second material of a dried gelatinous material (BA₂). In thisillustration, BA₁>BA₂. The gelatin could be dried in place after beingapplied onto and into the felt when in a liquid state. In this case,bio-absorption of the second material would allow tissue in growth intothe open area within the felt. The felted PGA would then remain in placefor a period of time as a mechanical support structure. Still anotherillustrative embodiment could use an open-cell PGA foam in place of thefelt described in the previous example. Again, many other permutationsare possible.

Referring still to FIG. 2, the reduced-pressure delivery member 268, orreduced-pressure delivery conduit, is associated with thereduced-pressure manifold 210. The reduced-pressure delivery member 268delivers reduced pressure to the tissue site, proximate the manifold210, and is thus shown on the second, tissue-facing surface 220 of thereduced-pressure manifold 210 to allow reduced pressure to be developedbetween the barrier member 212 and the tissue to be treated. Thereduced-pressure delivery member 268 may have delivery apertures (notshown) formed on a portion or have a shaped distal end to facilitatedelivery of the reduced pressure. The reduced-pressure delivery member268 may include multiple lumens, for example the reduced-pressuredelivery member 268 could be a dual lumen member with one lumendelivering a substance such as a fluid to the tissue site and the otherlumen delivering reduced pressure and removing fluids. Once treatment iscomplete, the reduced-pressure delivery member 268 may be removed fromthe patient's body, but the reduced-pressure manifold 210 may be left inplace for subsequent absorption.

Referring now primarily to FIG. 4, an alternative embodiment of thereduced-pressure manifold 210 is presented. The barrier member 212,which is formed from the first material 216, has the plurality ofapertures 222 filled with the second material 224. In addition, however,the second material 224 also forms an overlay 223 by overlaying theapertures 222 and the first surface 218 of the barrier body 214. Thesecond material 224 may be applied by coating the first surface 218 andfilling the apertures 222.

Referring now primarily to FIG. 5, another alternative embodiment of thereduced-pressure manifold 210 is presented. The barrier member 212,which is formed from the first material 216, has the plurality ofapertures 222. In addition, however, in this illustrative embodiment,the apertures 222 are not filled and the second material 224 forms theoverlay 223 by overlaying (but not filling) the apertures 222 and thefirst surface 218 of the barrier body 214. The second material 224 maybe applied by laminating the first surface 218. In still anotheralternative embodiment (not shown), the apertures 222 may be filled withthe second material 224 and a third material may be used to form anoverlay 223.

Referring now to FIG. 6, another illustrative embodiment of areduced-pressure manifold 310 is presented. The reduced-pressuremanifold 310 is analogous is many respects to the reduced-pressuremanifold 210 of FIG. 3, but a second material 324 is disposed in aplurality of apertures 322 to an extent that the second material extendsbeyond a second surface 320 to form a plurality of projections 336. Thereduced-pressure manifold 310 has a barrier member 312 having a barrierbody 314 formed from a first material 316. The barrier body 314 isformed with the plurality of apertures 322.

The projections 336 that extend from the apertures 322 form flowchannels 338 between the projections 336. The flow channels 338 may beparticularly advantageous if the first material 316 and the secondmaterial 324 are impervious to fluids. Variations in the size, shape,and spacing of the projections 336 may be used to alter the size andflow characteristics of the flow channels 338. The barrier body 314 maybe formed with a second plurality of apertures 326 through the barrierbody 314 that may have a third material 328 disposed in the apertures326. The third material has a bio-absorption term (BA₃) that may bevaried for further performance and control of the degradation, orabsorption, pattern of the reduced-pressure manifold 310.

In the embodiments, herein the plurality of apertures (e.g., 322 and 326of FIG. 6) may be over the whole surface of the barrier body or justpart of the barrier body. Some of the projections (e.g., 336 of FIG. 6)may not be formed from the second material but may be another materialfor delivering a medicine or other material into the area during thehealing process. In addition, while single substrate layers of materialare shown, many variations are possible. For example, a flexible supportor backing layer may be added (see, e.g., layer 642 below in FIG. 9).Further still, the materials may be a first thread material and a secondthread material that are woven or non-woven into the barrier member.

In an alternative embodiment, the barrier body 314 may be formed with asingle material and the thickness of the material may be varied. In thisway, for example, the projections 336 may be formed by increasing thethickness in portions of the barrier body 314. In this embodiment, thematerial absorption rate for the material is a constant, but theeffective absorption terms for various portions of the barrier body 314will vary as a function of the thickness. The thicker portions will takelonger to absorb than the thinner portions. Thus, a barrier member maybe formed from a material with a first plurality of material portionshaving a first thickness (t₁) and a second plurality of materialportions having a second thickness (t₂). The first thickness (t₁) isgreater than the second thickness (t₂). With this arrangement, thebarrier member has an effective bio-absorption term for the firstplurality of material portions that is greater than an effectivebio-absorption term for the second plurality of material portions.

Referring now primarily to FIG. 7, an illustrative reduced-pressuremanifold 410 is presented that is analogous in many respects to thereduced-pressure manifold 310 of FIG. 6. The reduced-pressure manifold410 has a barrier member 412 with a barrier body 414. The barrier body414 is formed from a first material 416 and has a plurality of apertures422. A second material 424 is disposed in the apertures 422. Thereduced-pressure manifold 410 is also formed with a plurality ofprojections 436 and concomitant flow channels 438 between theprojections 436. The projections 436 are made by extruding, attaching,or otherwise forming the projections 436 on a second (tissue-facing)surface 420 of the barrier body 414. The projections 436 may takevarious shapes, e.g., cylindrical, rectangular (in cross-section),trapezoidal (in cross-section), conical, spherical, hemispherical,cubed, etc., and may be made from the first material 416, secondmaterial 424, or another material.

Referring now to FIG. 8, another illustrative reduced-pressure manifold510 is presented. The reduced-pressure manifold 510 is formed with twomaterials: first material units 516 and second material units 524. Thefirst materials units 516 and second material units 524 may have thesame or different absorptions rates or terms. In this embodiment, thematerial units 516 and 524 are abutting and formed as an integralbarrier body 514. In one embodiment, the combined materials 516 and 524provide adequate strength and mechanical properties for the treatmentphase as reduced pressure is delivered through a delivery apparatus 568.One of the two materials is a quicker absorbing material and will absorbquicker than the other thereby allowing the treated tissue to chemicallycommunicate with other tissues. The chemical communication mayfacilitate continued or expedited healing.

While shown with two materials, it should be understood that, amongstthe many possible variations, a plurality of materials with differentabsorption terms (BA) cold be used to control the pattern and nature ofthe absorption of the reduced-pressure manifold 510. In addition, itshould be noted that while consistent patterns of material are shown inthis and the other embodiments, they may be varied as another controlfactor.

In the illustrative embodiment of FIG. 8, when the material with theshortest absorption term is absorbed, the remaining material will not berigidly connected. There will, thus, be little or no continuingmechanical action. It may also be possible to have a drug-deliverymaterial placed such that as the other materials are absorbed thedrug-delivery material becomes exposed and begins to delivery medicineto the tissue site.

Referring to FIG. 9, another illustrative embodiment of areduced-pressure manifold 610, or manifold unit, adapted for use in areduced-pressure delivery system, such as the reduced-pressure deliverysystem 100 of FIG. 1, is presented. The reduced-pressure manifold 610includes a flexible barrier 612, which comprises a spine portion 630 anda first wing portion 632 and a second wing portion 634. The first wingportion 632 and the second wing portion 634 are positioned alongopposite sides of the spine portion 630. The spine portion 630 forms anarcuate channel 640 that may or may not extend the entire length of thereduced-pressure manifold 610. Although the spine portion 630 may becentrally located on the reduced-pressure manifold 610 such that thewidth of the first wing portion 632 and second wing portion 634 areequal, the spine portion 630 may also be offset as shown in FIG. 9. Theextra width of the second wing portions 634 may be particularly usefulif the reduced-pressure manifold 610 is being used in connection withbone regeneration or healing and the wider reduced-pressure manifold 610is to be wrapped around any fixation hardware attached to the bone. Thethickness of the reduced-pressure manifold 610 may be less in thearcuate channel 640 than that in the wing portions 632, 634.

The reduced-pressure manifold 610 may further include materials that mayserve as a scaffold for new cell-growth, or a scaffold material may beused in conjunction with the reduced-pressure manifold 610 to promotecell-growth. Suitable scaffold material may include, without limitation,calcium phosphate, collagen, PLA/PGA, coral hydroxy apatites,carbonates, or processed allograft materials. Preferably, the scaffoldmaterial will have a high void-fraction (i.e., a high content of air).Such scaffold materials may have relatively rapid or extremely slowrates of bio-absorption. For example, scaffold materials formed fromcollagen would have relatively rapid absorption rates while scaffoldmaterials formed from calcium phosphate would have slow bio-absorptionrates.

A flexible backing 642 may be affixed or attached to the flexiblebarrier 612 to provide additional strength and durability to theflexible barrier 612. The thickness of the flexible barrier 612 and theflexible backing 642 may be less in the arcuate channel 640 than that inthe wing portions 632, 634. The reduced-pressure manifold 610 mayinclude a first plurality of projections 636 extending from the firstwing portion 632 and the second wing portion 634 on a second,tissue-face surface 620 of the reduced-pressure manifold 610. Theprojections 636 may be cylindrical, spherical, hemispherical, cubed, orany other shape, as long as at least some portion of each projection 636is in a plane different than the plane associated with the side of thereduced-pressure manifold 610 to which the projections 636 are attached.In this regard, a particular projection 636 is not even required to havethe same shape or size as other projections 636. The projections 636 mayinclude a random mix of different shapes and sizes. Consequently, thedistance by which each projection 636 extends from the manifold unit 610may vary, but may also be uniform among the plurality of projections636.

The placement of the projections 636 on the manifold unit 610 createsflow channels 638 between the projections. When the projections 638 areof uniform shape and size and are spaced uniformly on thereduced-pressure manifold 610, the flow channels 638 created between theprojections 636 are similarly uniform. Variations in the size, shape,and spacing of the projections 636 may be used to alter the size andflow characteristics of the flow channels 638.

The flexible barrier 612, which may include backing 642, may beconstructed of a bio-absorbable materials, as described above. Theprojections 636 may be formed as protrusions of a second material thatfill apertures in the flexible barrier 612, or barrier body 614, likeprojections 336 in FIG. 6, and the second material may have a differentbio-absorption term (BA₂) than the term of the flexible barrier body 614(BA₁). For purposes of illustration, it is assumed here that the secondmaterial has a bio-absorption rate greater than the material of theflexible barrier 614, i.e., a shorter absorption term.

A reduced-pressure delivery member 668 is positioned within the arcuatechannel 640 and is attached to the reduced-pressure manifold 610. Thereduced-pressure delivery conduit 668 may be attached solely to theflexible barrier body 614 or to the flexible backing 642, or thedelivery conduit 668 may be attached to both the flexible barrier 614and the flexible backing 642. The reduced-pressure delivery conduit 668includes a distal orifice 669 at a distal end of the conduit 668. Thereduced-pressure delivery conduit 668 may be positioned such that thedistal orifice 669 is located at any point along the arcuate channel640, but the reduced-pressure delivery conduit 668 is shown positionedsuch that the distal orifice 669 is located approximately midway alongthe longitudinal length of the arcuate channel 640. The distal orifice669 may be made elliptical or oval in shape by cutting the conduit 668along a plane that is oriented less than ninety (90) degrees to thelongitudinal axis of the reduced-pressure delivery conduit 668. Whilethe orifice 669 may also be round, the elliptical shape of the orifice669 increases fluid communication with the flow channels 638 formedbetween the projections 636.

In one illustrative embodiment, the reduced-pressure delivery conduit668 may also include vent openings, or vent orifices 650 positionedalong the reduced-pressure delivery conduit 668 as either an alternativeto the distal orifice 669 or in addition to the distal orifice 669 tofurther increase fluid communication between the reduced-pressuredelivery conduit 668 and the flow channels 638. The reduced-pressuredelivery conduit 668 may be positioned along only a portion of thelongitudinal length of the arcuate channel 640 as shown in FIG. 9, oralternatively may be positioned along the entire longitudinal length ofthe arcuate channel 640. If positioned such that the reduced-pressuredelivery conduit 668 occupies the entire length of the arcuate channel640, the distal orifice 669 may be capped such that all fluidcommunication between the conduit 668 and the flow channels 636 occursthrough the vent orifices 650.

The reduced-pressure delivery conduit 668 further includes a proximalorifice 652 at a proximal end of the conduit 668. The proximal orifice652 is configured to mate with a reduced-pressure supply conduit, suchas the reduced-pressure conduit 170 of FIG. 1, and ultimately to befluidly coupled to a reduced pressure source, such as reduced pressuresource 160 in FIG. 1. The reduced-pressure delivery conduit 668 mayinclude only a single lumen 644, but other embodiments of thereduced-pressure delivery conduit 668 may include multiple lumens suchas a dual-lumen conduit. The dual-lumen conduit may be used to provideseparate paths of fluid communication between the proximal end of thereduced-pressure delivery conduit 668 and the flow channels 636. Thesecond lumen may be used to introduce a fluid to the flow channels 636.The fluid may be filtered air or other gases, antibacterial agents,antiviral agents, cell-growth promotion agents, irrigation fluids,chemically active fluids, or any other fluid. If it is desired tointroduce multiple fluids to the flow channels 636 through separatefluid communication paths, a reduced-pressure delivery conduit may beprovided with more than two lumens. In some clinical situations, it maybe desirable to introduce a fluid that can accelerate or retard thedegradation (or absorption) of one or more of the degradable components,or materials, of the flexible barrier.

In operation of a system with manifold 610, reduced pressure isdelivered to the tissue site through the reduced-pressure manifold 610and is accomplished by placing the wing portions 632, 634 of theflexible barrier 612 adjacent the tissue site, which in this particularexample involves wrapping the wing portions 632, 634 around a voiddefect in the bone tissue site, e.g., bone fracture 106 of FIG. 1. Insuch a configuration, the reduced-pressure manifold 610 isolates thebone tissue site from surrounding soft tissue. Once treatment iscompleted, the reduced-pressure delivery conduit 668 may be removed andthe reduced-pressure manifold 610 may be left in place is absorb. In oneembodiment, the projections 636 are absorbed more quickly than theflexible barrier body 614, thereby permitting contact and chemicalcommunication between the bone tissue site and the surrounding softtissue much sooner than would otherwise occur.

Referring now FIG. 10, a reduced-pressure manifold 710 and a manifoldinsertion device 780 for use with a system for providing reducedpressure to a treatment site on a patient are presented. The tissue sitemight include bone tissue adjacent to a fracture on a bone of thepatient. The manifold insertion device 780 may include a delivery member782 inserted through the patient's skin and any soft tissue surroundingthe tissue site, e.g., bone. As previously discussed, the tissue sitemay also include any other type of tissue, including without limitationadipose tissue, muscle tissue, neural tissue, dermal tissue, vasculartissue, connective tissue, cartilage, tendons, or ligaments.

The delivery member 782 may include a tapered distal end 784 to easeinsertion through the patient's skin and soft tissue. The tapered distalend 784 may further be configured to flex radially outward to an openposition such that the inner diameter of the distal end 784 would besubstantially the same as or greater than the inner diameter at otherportions of the tube 782. The open position of the distal end 784 isschematically illustrated in FIG. 10 by broken lines 785.

The manifold delivery member 782 further includes a passageway 787 inwhich a flexible barrier 712, or reduced-pressure barrier, is duringinsertion. The flexible barrier 712 is preferably rolled, folded, orotherwise compressed around a reduced-pressure delivery member 768 toreduce the cross-sectional area of the flexible barrier 712 within thepassageway 787. The delivery member 768 may be a catheter or cannula andmay include features such as a steering unit and a guide wire 765 thatallow the manifold delivery tube 721 to be guided to the tissue site713.

The flexible barrier 712 may be placed within the passageway 787 andguided to the tissue site following the placement of the distal end 784of manifold delivery member 782 at the tissue site. Alternatively, theflexible barrier 712 may be pre-positioned within the passageway 787prior to the manifold delivery member 782 being inserted into thepatient. If the reduced-pressure delivery member 768 is to be pushedthrough the passageway 787, a biocompatible lubricant may be used toreduce friction between the reduced pressure delivery member 768 and themanifold delivery member 782.

When the distal end 784 has been positioned at the tissue site and thereduced-pressure delivery member 768 has been delivered to the distalend 784, the flexible barrier 712 and reduced-pressure delivery member768 are then pushed further toward the distal end 784, causing thedistal end 784 to expand radially outward into the open position. Theflexible barrier 712 is pushed out of the manifold delivery member 782,preferably into a void or space adjacent the tissue site. The void orspace is typically formed by dissection of soft tissue, which may beaccomplished by percutaneous devices. In some cases, the tissue site maybe located at a wound site, and a void may be naturally present due tothe anatomy of the wound. In other instances, the void may be created byballoon dissection, sharp dissection, blunt dissection, hydrodissection,pneumatic dissection, ultrasonic dissection, electrocautery dissection,laser dissection, or any other suitable dissection technique.

When the flexible barrier 712 enters the void adjacent the tissue site,the flexible barrier 712 either unrolls, unfolds, or decompresses froman initial insertion to an activation position as shown in FIG. 10.Although not required, the flexible barrier 712 may be subjected to areduced pressure supplied through the reduced pressure delivery tube 768to compress the flexible barrier 712. The unfolding of the flexiblebarrier 712 may be accomplished by either relaxing the reduced pressuresupplied through the reduced pressure delivery tube 768 or by supplyinga positive pressure through the reduced pressure delivery tube 768 toassist the unrolling process so that the flexible barrier 712 is anactivation position. Final placement and manipulation of the flexiblebarrier 712 may be accomplished by using endoscopy, ultrasound,fluoroscopy, auscultation, palpation, or any other suitable localizationtechnique. Following placement of the flexible barrier 712 andreduced-pressure delivery member 768, the manifold delivery tube 782 ispreferably removed from the patient, but the reduced-pressure deliverytube 768 associated with the flexible barrier 712 remains in situ toallow percutaneous application of reduced pressure to the tissue site.The flexible barrier 712 may be made of at least two different materialshaving different bio-absorption terms.

The flexible barrier 712 may be formed with a barrier body 714 of afirst material, which has a first bio-absorption term (BA₁), and formedwith a plurality of apertures 722. The apertures 722 may be filled witha second material 724, which has a second bio-absorption term (BA₂), oreven additional materials. The first bio-absorption term may be greaterthan the second. Radio-opaque members 748 may be included to helpconfirm placement of the manifold 710.

Once reduced-pressure treatment is completed, reduced-pressure deliverymember 768 may be removed and manifold 710 left to be absorbed. If thesecond bio-absorption term is selected to be less than thebio-absorption term of the first material, the barrier body 714 willnext have a plurality of open apertures 722 allowing chemicalcommunication between the treated tissue site and other tissue.

Referring now to FIGS. 11A-C, another reduced-pressure manifold 810 ispresented. In FIG. 11A, the reduced-pressure manifold 810 is shownconfigured for percutaneously insertion (insertion position). FIG. 11Bshows the reduced-pressure manifold 810 in the process of going from aninsertion position to an activation position, Finally, thereduced-pressure manifold 810 is shown in an activation position in FIG.11C just as the insertion device, e.g., sheath has been removed.

Referring primarily to FIG. 11A, a reduced-pressure delivery member 868has been inserted, such as by using a dilator and then a sheath (notshown), into a patient and brought to a place proximate the tissue to betreated, e.g., bone defect 106 of FIG. 1. Any reduced pressure held onthe delivery member 868 is released or a positive-pressure is applied onthe delivery member 868 to cause a flexible barrier member 812 to atleast partially unroll and begin to go from an insertion position to anactivation position. The delivery member 868 may have a slit or small,longitudinal opening 876 formed on a first side portion 878. The slit876 may allow the delivery member 868 to open when placed underpositive-pressure as will be explained. The flexible barrier 812 may beformed with at least two materials. A barrier body 814 is formed from afirst material and is formed with apertures 822 filled with a secondmaterial. Radio-opaque members 848 may be added at known locations, e.g.corners, to allow the placement of the manifold 810 to be verified andcontrolled.

A positive-pressure member or tube 890 having a distal end 892 is shownentering the reduced-pressure delivery member 868 in FIG. 11A. Thepositive-pressure member 890 has a flexible impermeable membrane 894,such a balloon, coupled to the distal end 892. The flexible impermeablemembrane may be pushed through delivery member 868 until near the distalend 869. Once near the distal end 869, positive-pressure may bedelivered through positive-pressure delivery member 868 to cause theflexible impermeable membrane 894 to inflate and thereby push outwardthe portion of delivery member 868 having slit 876. The portion ofdelivery member 868 and going from a lateral slit 877 to the distal end869 changes from an insertion position to an activation position asshown in FIG. 11B. The activation position urges the flexible barriermember 812 into its activation position used for treatment as shown inFIG. 11C. The membrane 894 is then deflated and the positive-pressuremember 890 is removed as is shown in FIG. 11C.

After the flexible barrier 812 is in place and the positive-pressuremember 890 is removed, reduced pressure may be supplied through deliverymember 868 to provide reduced pressure treatment to the tissue site.Once treatment is completed, it may desirable for the treated tissue toagain chemically communicate with other tissue. The second material inapertures 822 may absorb before the barrier body 814 and thereby formopen apertures that allow such chemical communication.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in a connection to any one embodiment mayalso be applicable to any other embodiment.

We claim:
 1. A reduced-pressure manifold for treating a tissue site, the reduced-pressure manifold comprising: a barrier member formed from a first material and having a first surface and a second, tissue-facing surface and wherein the barrier member is formed with a first plurality of apertures, the first material having a first bio-absorption term (BA₁); a second material disposed within the plurality of apertures and operable to form a temporary seal and wherein the second material has a second bio-absorption term (BA₂); wherein the first bio-absorption term is different than the second bio-absorption term (BA₁≠BA₂); and a reduced-pressure delivery member coupled to the barrier member for delivering reduced pressure to the second surface of the barrier member during treatment.
 2. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂).
 3. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂) and further comprising: a third material having a third bio-absorption term (BA₃); wherein the barrier member is formed with a second plurality of apertures; wherein the third material is disposed within the second plurality of apertures; and wherein the first bio-absorption term is greater than the third bio-absorption term (BA₁>BA₃).
 4. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂) and wherein the first material comprises a polymer material and the second material comprises gelatin.
 5. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂) and wherein the first material comprises a polyglycolic acid polymer material and the second material comprises gelatin.
 6. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂) and wherein the first bio-absorption term (BA₁) is at least one month and the second bio-absorption term (BA₂) is less than one week.
 7. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂) and wherein the first bio-absorption term (BA₁) is at least one week and the second bio-absorption term (BA₂) is less than three days.
 8. The manifold of claim 1 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂) and wherein the first bio-absorption term (BA₁) is at least two days and the second bio-absorption term (BA₂) is less than one day.
 9. A reduced-pressure pressure delivery system for percutaneous delivery of reduced pressure to a tissue site, the delivery system comprising: a reduced-pressure manifold formed from a first material having a first bio-absorption term and a second material having second bio-absorption term, the reduced-pressure manifold having an insertion position and an activation position; a reduced-pressure delivery member having a distal end with at least one delivery aperture for delivering reduced pressure to the tissue site; an insertion device for percutaneously delivering the reduced-pressure manifold and the distal end of the reduced-pressure delivery tube to the tissue site and transitioning the reduced-pressure manifold from the insertion position to the activation position; and wherein the first bio-absorption term is greater than the second bio-absorption term.
 10. The reduced-pressure delivery system of claim 9 wherein the insertion device comprises: a manifold delivery member having a distal end and a proximal end and having an insertion position and an activation position wherein the manifold-delivery member is operable to deliver the reduced-pressure delivery tube and the reduced-pressure manifold; wherein the reduced-pressure delivery member is formed with a longitudinal slit on a first side and having an open position and a closed position; a positive-pressure tube having a distal end and proximal end; an flexible impermeable member coupled to the distal end of the positive-pressure tube and having an insertion position and an activation position; and wherein, when the flexible impermeable member is in the activation position the flexible impermeable member is operable to move the reduced-pressure tube into open position whereupon the reduced-pressure manifold is moved to an activation position.
 11. The reduced-pressure delivery system of claim 9 wherein the insertion device comprises a delivery member having a distal end, wherein the reduced-pressure manifold is associated with the reduced-pressure deliver tube, and wherein the delivery member is sized to allow the reduced-pressure manifold and reduced-pressure delivery tube to move within the delivery member through the distal end.
 12. The reduced-pressure delivery system of claim 9 wherein the reduced-pressure manifold comprises a spine portion, a first wing portion, and a second wing portion, the first wing portion positioned opposite the second wing portion along the spine portion.
 13. The reduced-pressure delivery system of claim 9 wherein the reduced-pressure manifold member has a barrier body formed from the first material and formed with a first plurality of apertures, the first material having a first bio-absorption term (BA₁); wherein the second material is disposed within the plurality of apertures and operable to form a temporary seal and wherein the second material has a second bio-absorption term (BA₂); and wherein the first bio-absorption term is greater with respect to term than the second bio-absorption term (BA₁>BA₂).
 14. The reduced-pressure delivery system of claim 9, wherein the reduced-pressure manifold member has a barrier body formed from the first material and formed with a first plurality of apertures, the first material having a first bio-absorption term (BA1); wherein the second material is disposed within the plurality of apertures and operable to form a temporary seal and wherein the second material has a second bio-absorption term (BA2); wherein the first bio-absorption term is greater with respect to term than the second bio-absorption term (BA1>BA2); further comprising a third material having a third bio-absorption term (BA₃); wherein the reduced-pressure manifold member is formed with a second plurality of apertures; wherein the third material is disposed within the second plurality of apertures; and wherein the first bio-absorption term is greater than the third bio-absorption term (BA₁>BA₃).
 15. The reduced-pressure delivery system of claim 9 further comprising radio opaque markers operable to verify placement of the reduced-pressure manifold in the activation position.
 16. The reduced-pressure delivery system of claim 9 wherein reduced-pressure manifold comprises a barrier body having a first plurality of a barrier units formed from the first material and a second plurality of barrier units formed from the second material.
 17. The reduced-pressure delivery system of claim 9 wherein reduced-pressure manifold comprises a barrier body having a first plurality of a barrier units formed from the first material and a second plurality of barrier units formed from the second material; and wherein the first plurality of barrier units and the second plurality of barrier units laterally abut one another.
 18. A reduced-pressure treatment system comprising: an isolation device for isolating a tissue site from surrounding tissue for reduced-pressure treatment, the isolation device comprising a first material having a bio-absorption term (BA₁) and a second material having a second and different bio-absorption term (BA₂); a reduced-pressure source for providing a reduced pressure; and a reduced-pressure delivery conduit fluidly coupling the isolation device and the reduced-pressure source.
 19. The system of claim 18 wherein the isolation device comprises a flexible barrier member, the flexible barrier member comprising: a barrier body formed from the first material and having a first surface and a second, tissue-facing surface and wherein the flexible barrier member is formed with a first plurality of apertures; and wherein the second material is disposed within the plurality of apertures and operable to form a temporary seal.
 20. The system of claim 18 wherein the isolation device comprises a flexible barrier member, the flexible barrier member comprising: a barrier body formed from the first material and having a first surface and a second, tissue-facing surface and wherein a plurality of projections extend from the second, tissue-facing surface, the plurality of projections formed from the second material.
 21. The system of claim 20 wherein the flexible barrier member is formed with a first plurality of apertures, and wherein the second material is disposed within the plurality of apertures and is operable to form a temporary seal.
 22. The system of claim 18 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂).
 23. The system of claim 18, wherein the isolation device comprises a flexible barrier member, the flexible barrier member comprising: a barrier body formed from the first material and having a first surface and a second, tissue-facing surface and wherein the flexible barrier member is formed with a first plurality of apertures; wherein the second material is disposed within the plurality of apertures and operable to form a temporary seal; wherein the flexible barrier member further comprises a third material having a third bio-absorption term (BA₃); wherein the flexible barrier member is formed with a second plurality of apertures; wherein the third material is disposed within the second plurality of apertures; and wherein the first bio-absorption term is greater than the third bio-absorption term (BA₁>BA₃).
 24. The system of claim 18 wherein the isolation device comprises a fabric comprising a first thread material formed from the first material and a second thread material formed from the second material; and wherein the first material has a first bio-absorption term and the second material has a second bio-absorption term.
 25. The system of claim 18 wherein isolation device comprises a barrier body having a plurality of a first material units formed from the first material and a plurality of second material units formed from the second material; wherein the plurality of a first material units and the plurality of second material units laterally abut one another.
 26. The system of claim 18 wherein isolation device comprises a barrier body having a first surface and a second, tissue-facing surface, the barrier body formed from a first material and formed with a plurality of apertures; and a coating layer of the second material disposed on the first surface of the barrier body and disposed in the plurality of apertures.
 27. The system of claim 18 wherein the isolation device comprises: a flexible barrier member formed from the first material and having a first surface and a second, tissue-facing surface and wherein the barrier member is formed with a first plurality of apertures; wherein the second material is disposed within the first plurality of apertures and operable to form a temporary seal; and wherein the first bio-absorption term is greater than the second bio-absorption term.
 28. A method of manufacturing a reduced-pressure manifold, the method comprising the steps of: forming a flexible barrier member from a first material having a first bio-absorption term (BA₁), the flexible barrier member having a first surface and a second, tissue-facing surface; forming a first plurality of apertures in the barrier member; and disposing a second material in the first plurality of apertures, wherein the second material has a second bio-absorption term (BA₂) and wherein the first bio-absorption term is different than the second bio-absorption term (BA₁≠BA₂).
 29. The method of claim 28 wherein the first bio-absorption term is greater than the second bio-absorption term (BA₁>BA₂).
 30. The method of claim 28 further comprising the step of coupling a reduced-pressure delivery member to the flexible barrier member.
 31. A method for treating a tissue site with reduced pressure, the method comprising the steps of: positioning a reduced-pressure manifold formed from a first material and a second material proximate the tissue site; providing reduced-pressure to the reduced-pressure manifold; removing the reduced-pressure delivery member; allowing the first material to absorb within a first bio-absorption term (BA₁); and allowing the second material to absorb within a second bio-absorption term (BA₂) that is different than the first bio-absorption term.
 32. The method of claim 31 further comprising: fluidly coupling a reduced-pressure delivery member to the reduced-pressure manifold.
 33. The method of claim 32 further comprising: following application of reduced pressure and prior to allowing the first and second materials to absorb, removing the reduced-pressure delivery member.
 34. The method of claim 31 wherein positioning a reduced-pressure manifold further comprises using a reduced-pressure delivery member to deploy the reduced-pressure manifold, proximate the tissue site.
 35. The method of claim 31 wherein the reduced-pressure manifold comprises: a barrier member formed from the first material and having a first surface and a second, tissue-facing surface and wherein the barrier member is formed with a first plurality of apertures, and wherein the second material is disposed within the plurality of apertures and is operable to form a temporary seal.
 36. A reduced-pressure manifold for treating a tissue site, the reduced-pressure manifold comprising: a barrier member formed from a material and having a first surface and a second, tissue-facing surface and wherein the barrier member is formed with a first plurality of material portions having a first thickness (t₁) and a second plurality of material portions having a second thickness (t₂), wherein the first thickness (t1) is greater than the second thickness (t₂); wherein an effective bio-absorption term of the first plurality of material portions is greater than an effective bio-absorption term of the second plurality of material portions; and a reduced-pressure delivery member coupled to the barrier member for delivering reduced pressure to the second surface of the barrier member during treatment. 